Separation-optimized sequential injection method for rapid automated analytical separation of 90Sr in nuclear waste

An automated sequential injection (ST) analyzer was developed for analytical separations of Sr-90 in nuclear waste samples. The system provides rapid separation of Sr-90 from matrix and potential interfering elements using an Sr-selective extraction chromatographic column. After separation, Sr-90 activity can be determined by either on-line radiometric detection or off-line counting of collected fractions. The separation was investigated under automated conditions. Eluent compositions were determined that provide consistent, high, reproducible recoveries of Sr from the separation column. Procedures were designed with emphasis on rapid sample throughput. Using fraction collection, a set of eight samples can be processed in just over 1 h. Using on-line detection, each sample is separated and quantified in 22 min. The method was applied to nuclear waste supernate and Vitrified nuclear waste.